The overall aim of this project is to further develop a murine model of spinal cord injury (SCI) in order to gain a better understanding of the functional characteristics of reactive neural-glial progenitor cells (NGPCs) in the post-traumatic environment, and how these endogenous cells can be manipulated to increase functional recovery. The transgenic CNP-EGFP mouse, in conjunction with our contusive injury model, will increase the possibilities of investigation into the role of EGFP-positive NGPCs in the injured animal. Upon establishment and characterization of the model, I will test the novel hypothesis that a trophic factor not previously studied in SCI, Gro-alpha/KC, may play an important role in the proliferative response of NGPCs after injury, and may be used therapeutically to enhance insufficient proliferation acutely. There has been considerable research on NGPCs and related cell types (GPCs, O-2A cells, etc.) in embryonic and neonatal preparations. However, work in the adult, and especially after injury, is lacking. It is important to emphasize that the physiological and antigenic characteristics of these cells change after injury, and both the naive and injured adult populations are distinct from the neonatal NGPCs, and therefore warrant further investigation.